ArrayDimFetchAssignToAddCollectionCallRector

Change add dim assign on collection to an->add() call

 use Doctrine\Common\Collections\Collection;

 final class SetFirstParameterArray
 {
     /**
      * @var Collection<int, string>
      */
     public $items;

     public function setItems($item)
     {
-        $this->items[] = $item;
+        $this->items->add($item);
     }
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\Doctrine\TypedCollections\Rector\Assign\ArrayDimFetchAssignToAddCollectionCallRector;

return RectorConfig::configure()
    ->withRules([
        ArrayDimFetchAssignToAddCollectionCallRector::class,
    ]);